Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Hazards > 5.6- Fires in nature > Flashcards

5.6- Fires in nature Flashcards

1
Q

what is a wildfire?

A
  • uncontrolled rural fire- they destroy forests, grasslands and other areas of vegetation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

wildfires are known as what in Australia and North America?

A

bushfires

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

there are 3 main types of wildfire and all 3 can be present at the same time:

A
  • ground fire: slow smouldering ground base fire e.g. dry organic peat. No flames.
  • surface fire: the burning of leaf litter and low-lying vegetation. Can be high or low intensity.
  • crown fire: fire moves rapidly through the canopy. This fire has a dramatic effect on forested areas
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what are the conditions that encourage wildfires?

A
  • vegetation type/fuel characteristics

- climate and recent weather conditions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

explain how vegetation type/fuel characteristics encourages wildfires

A
  • influences the intensity (heat output) and rate of speed (degree of threat)
  • grassland= low heat output whereas forested areas= high heat output
  • eucalyptus and pine contain a lot of oil= burn easily
  • eucalyptus shed long strips of bark during a fire (firebrands) which can encourage the spread
  • in general, fine, dry material catches fire easily e.g. long grasses/twigs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

explain how climate/ recent weather conditions encourage wildfires

A
  • rainfall sufficient for vegetation to grow (fuel)
  • a distinct dry season- causes vegetation to dry up and become more flammable= why low risk of wildfires in UK
  • strong winds provide oxygen and help the fire spread and can in some circumstances, trigger lightening storms which are a natural trigger of wildfires
  • cyclical climate events like El Niño can cause favourable conditions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what is El Niño?

A

occurs every 6-8 years and involves the warming of the Pacific Ocean off the West Coast of South America. It affects global patterns of temperature and rainfall

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what are the main natural causes of wildfires?

A
  • lightning
  • volcanic eruptions
  • heat transfer heats vegetation ahead of the flames causing the fire to spread more rapidly- hot air rises (heat transfers vertically) which is why fires are so good at climbing. Experiments in Australia found that fires in a 20 degree slope advance 4 times the rate as fires on ground level
  • firebrands can be blown ahead of the flames and ignite new areas of forest- spot fires. Firebrands can also roll down hills and create spot fires
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

do natural or human causes, cause the majority of wildfires?

A

human causes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what are the main human causes of wildfires?

A
  • discarded cigarettes
  • poorly controlled campfires
  • arson

woodland that is particularly close to urban areas is most vulnerable of this sort of activity and known as ‘wildland-urban interfaces’

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

where are good examples of ‘wildland-urban interfaces’?

A

Los Angeles and Sydney

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what are a few primary social impacts?

A
  • loss of life
  • displacement (people forced to temporarily move elsewhere)
  • disruption to power supplies if power lines damaged by strong winds
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what are a couple secondary social impacts?

A
  • possible need for new employment and income stream

- behavioural adaptions based on wildife experience e.g. people may have to abide by new rules and regulations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what are a couple primary economic effects?

A
  • destruction of businesses

- loss of livestock and crops

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what are a few secondary economic effects?

A
  • cost of building or potential relocation
  • replacement of farm infrastructure,crops, livestocks etc
  • costs of future preparedness and mitigation strategies
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what are a few primary environmental impacts?

A
  • destruction of habitats and ecosystems- death of organisms impacts food chains and webs
  • short- term surge of carbon dioxide due to burning of trees (sinks)!!
  • atmospheric pollution resulting from smoke and water pollution as toxic ash gets washed into water courses
17
Q

what are a couple secondary environmental impacts?

A
  • increased carbon emissions impact on the (enhanced) greenhouse effect and climate change- depending n scale
  • lack of trees and vegetation causes depletion of nutrient stores, increased leaching and increased risk of flooding (reduced interception)
18
Q

what are a couple of primary political effects?

A
  • actions of emergency services

- pressure on local authorities and emergency services to coordinate and prioritise responses in the immediate aftermath

19
Q

what are a couple of secondary political effects?

A
  • develop strategies for preparedness and mitigation

- decisions regarding replanting forests, compensation, future regulations etc

20
Q

what are some short-term responses to wildfires?

A
  • emergency response teams attempting to put fire out
  • warning shared via social media platforms, TV and radio
  • evacuation
  • spraying water onto roofs of houses to prevent fire igniting them
21
Q

what is involved in long-term responses?

A
  • preparedness
  • mitigation
  • adaption
  • prevention
22
Q

what is involved in preparedness?

A
  • households write an emergency plan and buy in emergency supplies of food, water and medicine
  • authorities make emergency shelters
  • warnings are released using social media, TV and radio
  • red flag warning used in USA when weather conditions are perfect for serious fires (low humidity, strong winds and dry fuels)- residents in vulnerable areas are to be alert
23
Q

what is involved in mitigation?

A
  • satellites with infrared can detetc thermal variation
  • NASA developing drone tech to survey large areas
  • disaster aid and insurance can mitigate the effects of wildfires (to people and property in particular)
24
Q

what is involved in prevention?

A
  • public education to highlight the risks of campfires and BBQs in vulnerable areas
  • fire beaters available near recreational spaces so the public can put out small fires before they spread
    HOWEVER natural e.g. lightning is much more difficult
25
Q

what is involved in adaption?

A
  • planning regulations to enforce use of non-flammable building materials used in vulnerable areas
  • fire breaks created in forests to halt fire from spreading. However, fires in strong winds can ‘jump’ fire breaks. In the 2016 Alberta fire the wildfire jumped a 1km wide river
  • there is a school of thought that fires are a natural regenerative process within a forest ecosystem and they should be allowed to run their course

Hazards (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions